The natural gas hydrate, an unconventional gas resource, is paid widespread attention and researched by people in the world by virtue of the advantages of wide distribution, multiple types, big reserves and big energy density. Under the condition that difficulty in exploitation and utilization of traditional fossil energy resource rises at the current state, the natural gas hydrate is generally accepted as one of the most promising new efficient clean energies and has huge exploitation potential.
In a high-pressure and low-temperature environment, the natural gas and water may form a natural gas hydrate; when the condition for the existence of the natural gas is damaged, that is to say, the temperature rises at a given pressure or the pressure is dropped at the given temperature, the natural gas hydrate decomposes; the exploitation of the natural gas hydrate is to damage the phase balance of the natural gas hydrate to decompose the natural gas hydrate into natural gas and water for exploitation. In the exploitation of the natural gas hydrate, the horizontal well can enlarge the contact area efficiently, expand the decomposition range of the natural gas hydrate and accordingly increase the gas production rate; however, due to heterogeneity of the natural gas hydrate reservoir, a channeling phenomenon happens easily in the heat-injecting exploitation process, and the exploitation efficiency of the natural gas is affected seriously.